Abstract:

Aiming at the flight control problem of the air-breathing hypersonic vehicles, a variable gain observer based double-loop nonlinear feedback control scheme is proposed. Firstly, to obtain the unmeasurable state signals, a variable gain observer is designed. The model of the hypersonic vehicle is rewritten as the double-loop form by state transition. The adaptive observer gain is designed to ensure the stability and improve the robustness. On this basis, the hypersonic vehicle model is combined with the designed observer to construct a new strict feedback system. The backstepping method and dynamic surface method are used to design the controller. In addition, an extended state observer is involved to compensate the observation error and coupling term. The Lyapunov theory is used to prove the uniform bounded stability of the closed-loop system. Finally, through the numerical simulations, it is verified that the proposed control scheme can obtain the ideal command tracking in the presence of the large parameter uncertainties.

Key words:  Hypersonic vehicle, Variable gain observer； Output feedback； Extended state observer